Lario appeared to call time on the 30-year relationship Sunday, after the latest in a long line of ugly public spats over the media mogul’s obsession with young TV stars.

The final straw appeared to be the revelation that Berlusconi had attended the birthday party of a doe-eyed, blonde 18-year-old would-be model who referred to the mogul-turned-pol as “Daddy.”

Berlusconi in turn said on Monday he would only consider a reconciliation if Lario apologized for her remarks.

But the pair have long lived in separate houses. And if, as seems likely, the divorce goes ahead, Lario could seek a huge chunk of Berlusconi’s $6.5 billion fortune, experts said.

Cesare Rimini, a celebrated Italo divorce lawyer from Milan, told La Stampa that if Lario was determined to go for a big pay-out, “there was sure to be a lawyer who would do it for her.”

One analyst, who would not be named, suggested any really costly divorce settlements might dampen Mediaset’s enthusiasm for high-profile purchases. In the past few weeks, the Italo broadcaster has frequently been named as a possible buyer for Britain’s ailing ITV network.

Political commentators note too that Lario appears the only person capable of upsetting the plans of an Italian leader who is king of virtually all he surveys — if a messy divorce provides a focal point for political opposition, or should sympathy for Lario dent his poll ratings.

Berlusconi controls three of the seven national TV channels, all part of his Mediaset empire, and has considerable influence over who runs the three RAI pubcaster channels.

Last year, he successfully forced through a handy immunity law, which meant the courts had to drop corruption charges pending against him. This was made possible by the healthy majority he enjoys in both chambers of Parliament. In addition, the political opposition in Italy is feeble and fragmented.

James Walston, Professor of International Relations at the American University of Rome, said if the divorce was messy it would be “a big liability.” “It messes up his image and his media control,” he said.

Berlusconi, who is Italy’s second-richest man, has three children aged 20, 22 and 24 with Veronica.

However, it is his two children by his first marriage who play the most prominent roles in his business empire. Son Piersilvio is vice-president of Mediaset while daughter Marina chairs holding company Fininvest.

Rimini predicted the real battle would be over who finally inherits what from the media mogul’s multi-billion dollar media and entertainment empire.